At heights of 10 to 30 km above the earth's surface, cosmic rays are continually striking oxygen and nitrogen atoms and producing π mesons, both charged and neutral. follow one of the π+ mesons on its way down. observer b is in the reference frame attached to the particle ( rocket frame ) and determines the average life of the meson to be 2 55 × 10-8s. suppose that the rocket frame moves at a speed u = 12c/13 relative to the earth's reference frame, and that observer a at rest in the earth's frame determines the average lifetime of the π-meson to be 6.63 × 10-8s. (a) how far does the π-meson move in the laboratory frame between its birth and decay ? (b) according to observer b how far does the particle move between birth and decay in the laboratory frame? note: you may ignore the effects of gravity on the particle motion which you should treat accong to chunics.